This invention relates to ball throwing devices, and more particularly to such a device which is adjustable to pitch balls at various speeds, spins and directions.
U.S. Pat. Nos. 3,774,584; 4,193,591; and 4,760,835 have common ownership with the instant application and they disclose ball throwing devices in which a pair of rotary wheels are independently adjustable in speed to achieve the throwing of a ball with wide variations in velocity and curvature. However, neither the foregoing patents nor any other known patent provides for adjusting the speed and/or direction of such wheels in small increments by means which are difficult to detect by a batter from the distance of the pitching mound. Thus, a practicing batter is given advance information as to the type and speed of pitch to be delivered, and thereby receives no training in instantaneous recognition of various pitches in the manner delivered by a pitcher in actual play.